The quest for nuclear fusion

With its promise of virtually unlimited clean energy, nuclear fusion has long been a goal of physicists. With the enormous ITER experimental reactor under construction in the south of France, Antony Funnell takes a look at the feasibility of replicating the Sun here on Earth.

ABC Future Tense Wednesday 25 February 2015 Antony Funnell


With its promise of virtually unlimited clean energy, nuclear fusion has long been a goal of physicists. With the enormous ITER experimental reactor under construction in the south of France, Antony Funnell takes a look at the feasibility of replicating the Sun here on Earth.

It’s shaping up as a busy time in the south of France, even though the holiday makers from Paris aren’t expected until at least mid-April.

Teams of construction workers and scientists are flocking to the region tasked with building one of the world’s largest experimental facilities—a giant nuclear reactor that will take at least another ten years to complete.

Christened ITER (Latin for ‘the path’ or ‘journey’), the $US20 billion reactor is like no energy plant ever constructed. The project’s goal is to save the world from environmental catastrophe by providing humankind with a clean, safe energy source. Its mission is to replicate the Sun by producing power through a nuclear process known as fusion.

I think there are a lot of sceptics attracted by the fact that so much has been promised of fusion for so long and it hasn’t been achieved.

Listen to the ABCRadioNational Excerpt: A piece of the Sun – Nuclear fusion

A conventional fission reactor splits atoms in order to generate energy, but the fusion process works the other way—it forces atoms together under great heat. The atoms it uses are relatively abundant in nature, such as those from the chemical elements hydrogen and lithium.

It would be the solution to our energy problems forever if they can get it to work,’ says Daniel Clery, deputy news editor of Science magazine and author of the book A Piece of the Sun: The Quest for Fusion Energy.

There is so much hydrogen in the oceans and lithium in the ground that you could run fusion reactors for millions of years and never run out of fuel. It doesn’t produce pollution, so it doesn’t warm the climate.

The other major benefit, says Clery, is that the fusion process doesn’t produce the sort of radioactive waste that has plagued the traditional nuclear power industry and limited its expansion.

‘It produces a little bit of waste at the end of a reactor’s life,’ says Clery. ‘The reactor itself is slightly radioactive, so you’d need to bury it for 50 years to let it cool down, but it’s not like the waste that is produced by a traditional fission reactor where the waste is highly toxic and last hundreds of thousands of years. So it’s a very different ball game.’

The quest for fusion energy has been a long one. Australian physicist Mark Oliphant was one of its pioneers back in the 1930s. Since that time several functioning fusion reactors have been built, but none have passed the experimental stage, let alone shown signs of commercial viability.

The major stumbling block is achieving net energy. For fusion to occur, a plasma of light atoms has to be heated to a temperature in excess of 100 million degrees celsius. Scientists have been able to do that using a special donut-shaped chamber called a Tokamak which uses a magnetic field to keep the super-heated plasma from touching the sides of the containment vessel.

So nuclear fusion is by no means a theoretical concept, it can work.

The problem, however, is that no fusion reactor that’s ever been built has managed to produce enough energy to make the process economically viable. In other words, it’s taken as much energy to power the reactor as the reactor itself has produced.

Overcoming that imbalance has frustrated nuclear scientists for decades, but it’s also brought them closer together.

‘Most of the international program is now consolidated around ITER as the next step fusion experiment,’ says Associate Professor Matthew Hole from the Plasma Research Laboratory at the Australian National University.

‘If you want to be in the game, you must be part of the ITER project. In some sense there is an analogy here to high energy particle physics; if you want to do high energy particle physics you need to be involved in something like the Large Hadron Collider.’

The ITER project represents a collaboration between the European Union and six nations: the United States, China, India, South Korea, Japan and Russia. A partnership agreement was signed in 2005 but on-site construction in Saint Paul-lez-Durance, northeast of Marseille, didn’t begin until late 2014.

The experimental reactorwill have the initial task of producing 500 megawatts of thermal power from 50 megawatts of input heating power for at least 300 seconds.

That may not sound like much of an achievement, but scientists are convinced that once the reactor can prove its efficacy, great things will follow. Still, Daniel Clery accepts that the project has as many detractors as it does enthusiasts.

Although Australia isn’t one of the ITER signatories, the Australian scientific community is keen to ensure it finds a seat at the fusion research table.

‘There are ways in which Australia can participate both in the ITER science and also the ITER project itself, at a scale that makes sense for Australia and at a scale for which there is significant leverage of that international science back to Australia,’ says Matthew Hole, the chair of the Australian ITER Forum, a collective of scientists and engineers keen to be part of this historic experiment.

‘It’s a low entry ticket, if you like, to a very big program.

‘There’s a framework called the International Tokamak Physics Activity, which is an international framework for ITER relevant research, and we think there is an opportunity for Australian scientists to participate in that.’

According to Hole, success in southern France should pave the way for the first commercially viable fusion power-station, but he cautions that that advance could still be some way off: ‘ITER is really a pre-prototype power plant in the sense that it’s intended to deliver the physics and engineering that we need to understand in order to be able to put together a prototype commercial power plant.

‘So ITER is really the last physics research experiment before a prototype power plant. For that reason alone, I think if you look at the chronology of experiments and if you look at the state of understanding of the field at present, I think it is likely, indeed very plausible, that fusion will be able to meet its ambition of being able to produce power by the middle of the century.’

ITER might be the international focal point for fusion research, but that doesn’t mean it’s the only game in town. High-level experimentation is still being conducted at the Joint European Torus facility (JET) in Oxfordshire in the UK.

In late 2014 the giant American aircraft manufacturer Lockheed Martin surprised many when it issued a media release claiming to have made advances in what it called a ‘compact’ fusion reactor. It will be so small, a company spokesman declared, that it would fit on the back of a truck.

Lockheed Martin claims its device could be ready for commercialisation within a decade. Clery is sceptical: ‘They’ve taken a couple of old techniques and combined them together, but at the moment all they’ve done is computer simulations.

‘Personally I think their predictions were enormously over-enthusiastic, but you never know, they might have success and they might be building a working prototype in 10 years.’

Hole also has reservations. He says the company is yet to match its PR claim with any substantive scientific proof.

‘When I was at the Fusion Energy Flagship conference, there was no representative there from Lockheed Martin. They didn’t turn up to the meeting. They haven’t given any detailed information about their experiments. The information is not there. It’s great to have these ambitions, but it is not substantiated by any scientific evidence.’

shining sun
A piece of the Sun – Nuclear fusion
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Sunday 22 February 2015
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For the record, the company also declined an interview request from RN.

‘I think Lockheed Martin finds itself in an environment where the defence contracts have been dwindling because the US has reduced its expenditure in developing new technology, military technology in particular, so it’s seeking to diversify,’ speculates Hole. ‘I understand Lockheed is a commercial company, but at the very least you need to substantiate any claim that you make with evidence.’

While Lockheed Martin appears less than keen to share, that certainly isn’t the case with ITER. In fact, according to Clery, transparency is one of its key strengths.

‘The ITER project is international, entirely open, so no one country or company is going to monopolise it,’ he says. ‘The whole project is designed so that all of the partners are involved in making most of the parts, so that everyone gains the expertise that is going to be needed in the future, and we will all get the benefit if it succeeds.’

Excavation work on a 130 metre ‘seismic isolation pit’ was completed in August last year allowing for work to begin on the reactor complex proper. The giant Tokamak fusion chamber and its supporting structure is expected to weigh around 400,000 tonnes and reach seven stories in height. The chamber itself will take up to five years to construct and won’t be ready for testing before 2020.